The effect of linear shear current on head-on collision of solitons
The effect of linear shear current on head-on collision of solitons
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DOI：
10.1063/5.0151627
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发表时间：
2023-06
影响因子：
4.6
通讯作者：
R. Ertekin;M. Hayatdavoodi
中科院分区：
文献类型：
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作者：
R. Ertekin;M. Hayatdavoodi
利用高级格林-纳格迪 (HLGN) 理论研究了线性剪切流存在下两个孤立波的正面碰撞。时域仿真中采用有限差分法求解HLGN模型。初始值是通过存在线性剪切流的情况下孤立波的稳态解获得的。考虑不同速度的剪切流来评估它们对孤立波碰撞的影响。研究了剪切流下正面碰撞过程的三个方面，即波高程、速度场和粒子轨迹。结果表明，背景线性剪切流显着影响迎面碰撞过程中的波高程、速度场和粒子轨迹。据观察，在存在水流的情况下，波高在最大表面位移附近较窄，在静水位附近较宽。还表明，在海底附近，水平速度与海流方向相反，而在自由表面附近则跟随海流方向。相反的剪切流导致流体场中形成涡流。在碰撞点，涡流出现在较低的垂直位置，并向当前方向的上游移动。沿着存在剪切流的粒子轨迹，观察到粒子在正面碰撞后不会返回到其初始位置，并且粒子的循环运动随着电流速度的增大而变小。
Head-on collision of two solitary waves in the presence of linear shear currents is studied by the use of the High-Level Green–Naghdi (HLGN) theory. The finite difference method is used to solve the HLGN model in the time-domain simulation. The initial values are obtained by the steady solution of solitary waves in the presence of linear shear currents. Shear currents with different velocities are considered to assess their effect on the solitary-wave collision. Three aspects of the head-on collision process in the presence of shear current are studied, namely, the wave elevation, velocity field, and particle trajectory. Results show that the background linear shear current significantly affects the wave elevation, velocity field, and particle trajectory during the head-on collision. It is observed that in the presence of the current, the wave elevation is narrower near the maximum surface displacement and is wider near the still-water level. It is also shown that near the seafloor, the horizontal velocity is opposite of the current direction, while it is following the current direction near the free surface. The opposite shear current results in the formation of a vortex in the fluid field. At the point of the collision, the vortex appears at a lower vertical position and shifts upstream of the current direction. Following the particle trajectories in the presence of the shear current, it is observed that the particles do not return to their initial positions after the head-on collisions, and the loop motions of the particles become smaller with larger current velocities.